1. Field of the Invention
The present invention relates to a method of monitoring milking conditions when milking is made by a milking machine.
2. Description of the Relevant Art
Generally, when a milking machine is employed to milk a cow, it is necessary to determine whether the milking is finished at a proper time. If the milking is made excessively, cellular tissue of the nipples of a cow is left under vacuum. Thus, there is increased danger that the cow develops mastitis, and the presence of somatic cells in the milk is increased. Accordingly, it is very important that completion of milking is determined exactly and surely.
Thus, recently, a milking completion determination method using a flow rate sensor is adopted to automatically remove a milking unit.
In the determination using the flow rate sensor, a STET of milk is measured by the sensor and when an actually measured value of the flow rate at the end of milking is lower than a predetermined reference value of the flow rate (for example, about 0.2 to 0.8 kg/min), it is determined that the milking is finished. The present Applicant has proposed, for example in Japanese Utility Model Unexamined Publication No. 63-68758, a milking completion detection apparatus in which a time during which an actually measured value of the flow rate of milk is lower than a reference value of the flow rate of milk is integrated and when the integrated value exceeds a predetermined value the milking is finished.
Usually, teat cup liners are attached to four nipples of a cow, respectively, so that the four nipples are milked simultaneously, while it is rare that the milking for all four nipples is finished simultaneously and the milking completion time for each nipple is often scattered. Accordingly, if the finishing time for milking a first nipple is much earlier than those for the other nipples, the first nipple is subjected to excessive milking. However, in the conventional completion determination method, it is difficult to detect such stepwise reduction of the flow rate of milk.
Further, in order to avoid potential mastitis and increased somatic cells in milk due to the excessive milking, it is put into practice that the completion of milking is determined when a slight amount of milk remains in a nipple. In this case, however, it is necessary to set the reference value of the flow rate of milk to about 0.8 to 1.0 kg/min, for example. However, as show in FIG. 8; there are a well milking cow C1, a poorly milking cow C2, and a very poorly milking cow C3; and individual cows are different from one another. Thus, even if the reference value of the flow rate is merely set to a large value, there is a problem that the completion of milking is determined at the beginning of the milking in the case of the cow C3. On the other hand, for the cow C1, it is necessary to set the reference value of the flow rate to a larger value (for example, 1.0 to 2.0 kg/min) in view of the protection of the cow from excessive milking. In either case, the conventional determination method of setting the uniform reference value of the flow rate is difficult to determine the completion of milking exactly and surely.